Fahgedaboutit - the original Hard Rock Cafe is in Empire, Colorado (west of Denver). It has been open, under the same name, for about 100 years. It was named “Hard Rock” for the local mining style, rather than a musical one. Coincidence? I think not.
… and the link to the Mailbag column is: http://www.straightdope.com/mailbag/mhardroc.html
There was also a Doors album called Morrison Hotel released about '69 or '70 which had a picture of a bar called the Hard Rock Cafe on the inside cover. This place was definitley not a hip swanky club, don’t know if it was in Co. or not,